feickee



- UNITED STATES PATENT OFFICE,

THOMAS n. nnNcnY AND EDWARD P. rnIoKnn, OF NORTHAMPTON, MAss,

-ASSIGNORS OF ONE-HALF TO E. WOOD, onsAMn PLACE.

PROCESS OF FORMING ORNAMENTAL DESIGNS ON METAL.

SPECIFICATION forming part of Letters Patent. No. 268,486, dated December 5, 18( 2.

pplication filed June 9, 1882. (No specimens.)

plication of acids thereto uponexposed portions of the surface constituting figures or characters, technically termed, biting in, the

object being to greatly simplify the art of so producing characters and figures upon metal, and to provide improved means for reproducing or duplicating said figures to any exten at very small expense. 20 In producing characters and ornamental figures upon metal heretofore by the bitingin process it has been customary to cover a polished metal plate with a composition technically called ground, consisting of a var- 2 5 nish-like substance, and then trace the design thereon by a pointed tool, which lays bare the metal wherever it goes, after which the acid is applied, which corrodes the metal on the lines made through the ground, and finally said 0 ground is washed off, leaving the distinct corroded lines; or, said characters have been produced on the metal by transferring them, by means of a thin paper, from an engraved and inked plate, to said metal, then covering said 5 ink-characters and the metal surrounding them with a thin varnish ground impermeable to turpentine, excepting upon the inked lines, next washing out the said ink-lines with benzine or turpentine, and then applying acid upon the 40 metal exposed by said lines, and finally washing off the groundand acid after the latter has a sufficiently corroded the metal to cause the' said characters to appear distlnctly upon the metal. p

5 i It will be seen that the above-described processes involve many operations and the employment of skilled operatives i i To carry our invention into effect, We cover the metal with a thin ground of guiac-varnish,

and having prepared a soft or elastic-faced o stamp, of rubber, cork, or leather, bearing upon its face the design or characters to be reproduced on the metal, We moisten the face of said stamp with a paste of some suitable fixed alkalisucl1 as potash or soda-and pressing 5 said stamp upon said ground, the portions of the latter corresponding to the figures upon said stamp are at once removed by the action of said alkali. Acid is now applied to the metal from which the alkali removed the ground, and is left to sufficiently corrode, when the acid and ground are washed off, leaving a clearly defined figure on the metal, corresponding to that on said stamp; or, in a few words, we apply to the metal a ground of suitable material to resist theaction of the metal-corrodin g acid, and with an elastic-faced stamp having the desired characters formed upon its face, to whichis applied agroundremoving substance,

we imprint the desired figures through said ground to permit the acid to act upon the surface of the metal from which theground is so removed, and produce the counter-part of the figure on said stamp. r

This process is especially advantageous for ornamenting swords, various articles of wearing-apparel ornaments, for fixing manufacture ers names and marks upon all kinds ofcutlery, and for any purposewherein'metal of which an article ismade is susceptible of corrosion 8Q by acid,and may be used in ornamenting glass.

We do not limit ourselves to the use of guiacvarnish (gum-guiac mixed withalcohol) as a ground, nor to the use ofan alkali as agroundremoving element to be used with the ornameutingstamp, since a common varnish consisting'of drying .oil, turpentine, and African copal may be used for the ground, and benzine be used on the stamp for removingsaid ground to form the figurelines, but not with so good 0 results as by the use of guiac-varnish and an alkali.

What we claim as our invention, is-

1. The process of producing bitten-in figures and characters upon metals, which con- 5 sistsin applyingaground to the surface there of, consisting of 'gum-guiac varnish, and then cutting figure forms through said ground to expose the metal beneath by applyingthereto an elastic-faced figure-bearing stamp having applied thereto a ground-removing element consisting of an alkali, then applying acid to said figure forms, and finally washing off said acid and ground, all substantially as set forth.

2. The improvement, in processes for ornamentingmetals by the application of acid thereto through figure forms in a ground of gun]- ro guiac varnish applied to the metal, which consists in producing said figure forms by applying a figure-stamp to said ground, having upon its face an alkalineground-removing element, all substantially as described.

THOMAS N. HENGHY. EDWD. 1. FEIOKER.

Witnesses:

EDWARD E. W001), J r., WALTER A. TURNER. 

